PHP Comtrust SOAP api Response Code 5000

I am using Comprust payment api and am developing a SOAP wrapper to call Comtrust functions. And currently use Comtrust demo account by following their documentation and getting the following answer:

stdClass Object ( [RegisterResult] => stdClass Object ( [ResponseCode] => 5000 [ResponseDescription] => Request is not permitted or not authenticated properly [UniqueID] => 1942d0d0-37f5-4504-951e-3343f9b86ea7 [version] => 2.0 [PaymentPortal] => [TransactionID] => ) )

      

        
        
        
      

    

I am using the following code:

 $client = new SoapClient("https://demo-ipg.comtrust.ae:2443/MerchantAPI.svc?singleWsdl");
    try {

        $result = $client->Register(array("request" => array(
            'Customer' => 'Demo Merchant',
            'Channel' => 'Web',
            'Address'   => 'demo-ipg.comtrust.ae',             
            'Language' => 'en',
            'Password' => 'Comtrust',
            'version' => '2.0',
            'Amount' => '99.98',
            'Currency' => 'AED',
            'OrderID' => '123',
            'OrderInfo' => 'Test Info',
            'OrderName' => 'Test Name',
            'ReturnPath' => 'http://127.0.0.1/jd_ecommerce/',
            'TransactionHint' => 'CPT:Y'
       )));
        print_r($result);
    }catch (Exception $e)
    {
        echo 'Caught exception: ',  $e->getMessage(), "\n";
    }

      

        
        
        
      

    

I have a certificate file that is in .pfx format and a password. My question is how to transfer a .pfx file with a SOAP envelope. Does anyone have a similar face?

Please, help!!

Thank you in advance